The present invention relates to semiconductor devices which conduct such operation as converting reflected light from a manuscript paper into an electric signal. The present invention especially relates to a semiconductor device which can conduct contact reading with a light-receiving portion which can correspond to the manuscript in its measurement by one to one.
FIG. 1 shows a typical diagram of a conventional contact reading type device.
Referring to FIG. 1, the contact reading device is composed of a photo cell array 22 consisting of amorphous silicon and the like, disposed on an insulative substrate 21 such as glass or alumina; an IC 23 provided with either a function to successively read the electric output of a photo cell, or a function to amplify the electric output even more; and a wiring group 24 which connects the photo cell array 22 and the IC 23.
In a case when a conventional contact reading semiconductor device reads an A4 size manuscript, if a resolution corresponding to 8 dots is necessary to read a 1 mm portion of the manuscript, approximately 2000 photo cells arranged at intervals of 125 .mu.m will be necessary. Therefore, the number of wirings to pick up the signal from each photo cell becomes very large, and thus more than ten ICs for conducting signal processing will be necessary. And so, the process to connect the wiring and the IC is difficult, and is a factor which reduces the yield. Furthermore, as the wiring group 24 is formed so that IC 23 can be mounted on the insulative substrate 21, the area of the insulative substrate necessary for the wiring will be several ten times compared to the total area of photo cell array 22, and this will cause a reduction in the ability to manufacture at low cost. Also, as the wiring connecting the photo cell and the IC must be made of different lengths, their wiring capacity and wiring resistance differ, affecting the obtained signal, and the signal processing circuit to correct the effect will be complicated and thus high accuracy will be difficult.